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Publication numberUS20050007756 A1
Publication typeApplication
Application numberUS 10/866,779
Publication dateJan 13, 2005
Filing dateJun 15, 2004
Priority dateJul 9, 2003
Also published asUS7178962
Publication number10866779, 866779, US 2005/0007756 A1, US 2005/007756 A1, US 20050007756 A1, US 20050007756A1, US 2005007756 A1, US 2005007756A1, US-A1-20050007756, US-A1-2005007756, US2005/0007756A1, US2005/007756A1, US20050007756 A1, US20050007756A1, US2005007756 A1, US2005007756A1
InventorsHong-Tien Yu, Jin-Jei Wu
Original AssigneeChunghwa Picture Tubes, Ltd.
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Reflecting apparatus for backlight module of flat panel display
US 20050007756 A1
Abstract
A reflecting apparatus for a backlight module of a plane display is disclosed. The backlight module includes a light guide distal from the reflecting apparatus, and a plurality of diffusers. The apparatus comprises a light source, a reflector, and two substantially parallel sets of partially overlapped light deflectors wherein a gap exists between either two adjacent light deflectors of the same set or one light deflector and the reflector. A portion of emitted light is directed to the light guide after being reflected from the reflector. The remaining portion of light is directed to the light guide either after it has been deflected by the light deflectors or deflected by the light deflectors prior to being reflected by the reflector. Parallel light received at the light guide is deflected to the plane display as a backlight source of the plane display after passing the diffusers.
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Claims(7)
1. A reflecting apparatus for backlight module of plane display, the backlight module including a light guide distal from the reflecting apparatus and a plurality of diffusers, said reflecting apparatus comprising:
a light source;
a reflector having a concave surface and a focus on the light source; and
two substantially parallel sets of a plurality of light deflectors at one side of the reflector wherein a gap exists between either two adjacent light deflectors of the same set or one light deflector and the reflector,
wherein a portion of light emitted from the light source is directed to the light guide after being reflected from the reflector, a remaining portion of light is directed to the light guide after the remaining portion of light has been deflected by the light deflectors, and light received at the light guide is deflected to the plane display as a backlight source of the plane display after passing the diffusers.
2. The reflecting apparatus as claimed in claim 1, wherein a cross section of the reflector is a parabola.
3. The reflecting apparatus as claimed in claim 1, wherein the light reflector is a concave lens of either a cone or cylinder.
4. The reflecting apparatus as claimed in claim 1, wherein light is substantially parallel directed to the light guide.
5. The reflecting apparatus as claimed in claim 1, wherein light is deflected by the light deflectors prior to being reflected by the reflector.
6. The reflecting apparatus as claimed in claim 1, wherein each of the light deflectors is partially overlapped by one or two adjacent light deflectors of the same set.
7. The reflecting apparatus as claimed in claim 1, wherein the light source is a CCFL (cold cathode fluorescent lamp) or LED (light emitting diode).
Description
BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to reflectors and, more particularly, to a reflecting apparatus of the backlight module for a plane display with improved characteristics.

2. Description of Related Art

Plane displays such as LCDs (liquid crystal displays), and the like have become the dominant type of displays in recent years due to their advantageous characteristics (e.g., lightweight, compactness, etc.)

A backlight module is typically mounted in the plane display as the light source of the display. With reference to FIG. 1, there is shown a conventional backlight module comprising a light source 60, a light guide 4, two diffusers 51 and 52, and a reflector 70 having a concave surface. Light is emitted from the light source. Next, light is directed to the light guide 4 after being reflected by the reflector. Next, light is deflected to the display after passing the diffusers 51, 52. Increasingly larger plane displays are becoming the dominant factor in the market. As such, additional light sources are required for enabling the display to have a sufficient and evenly-dispersed brightness. However, light is scattered and wasted during the reflection (i.e., low efficiency). Further, heat may accumulate excessively due to poor ventilation of the well-known arrangement. Also, the provision of additional light sources can consume electrical energy significantly. Hence, the conventional backlight module is not satisfactory for users of large plane displays.

Therefore, it is desirable to provide a reflecting apparatus for the backlight module of a plane display in order to mitigate and/or obviate the aforementioned problems.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a reflecting apparatus, for reusing or collecting the scattered light to increase the intensity of reflected light, and to increase the efficiency of heat dissipation of the backlight module for preventing overheating of the light source.

The reflecting apparatus of the present invention is mounted in a backlight module of a plane display. The backlight module includes a light guide distal from the reflecting apparatus, and a plurality of diffusers. The reflecting apparatus includes a light source; a reflector having a concave surface and a focus on the light source; and two substantially parallel sets of a plurality of partially overlapped light deflectors at one side of the reflector wherein a gap for ventilation exists between either two adjacent light deflectors of the same set or one light deflector and the reflector. A portion of light emitted from the light source is directed to the light guide after being reflected from the reflector, the remaining portion of light is directed to the light guide either after it has been deflected by the light deflectors or deflected by the light deflectors prior to being reflected by the reflector, and parallel light received at the light guide is deflected to the plane display as a backlight source of the plane display after passing the diffusers. By utilizing the present invention, intensity and brightness of light received at the light guide is significantly intensified without adversely consuming electrical energy.

Other objects, advantages, and novel features of the invention will become more apparent from the detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a conventional reflecting apparatus for the backlight module of a plane display;

FIG. 2 is a schematic view of a first preferred embodiment of reflecting apparatus for the backlight module of a plane display according to the invention;

FIG. 3 is a schematic view of a second preferred embodiment of reflecting apparatus for the backlight module of a plane display according to the invention;

FIG. 4 is a sectional view of FIG. 2;

FIG. 5 is a sectional view of FIG. 3; and

FIG. 6 is a schematic view of the backlight module incorporating the reflecting apparatus of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to FIGS. 2 and 4, there is shown a reflecting apparatus for the backlight module of a plane display constructed in accordance with a first preferred embodiment of the invention. As shown, the reflecting apparatus comprises a cylindrical light source 1, a reflector 2 having a concave surface and a focus on the light source 1, and two substantially parallel sets of a plurality of light deflectors 3 disposed at one side of the reflector 2. A portion of light emitted from the light source 1 is substantially parallel directed to a distal light guide (not shown) after reflecting from the reflector 2. The remaining portion of light is also directed to the distal light guide after it has been deflected by the light deflectors 3 in which deflected light is substantially parallel from the light deflectors 3 belonging to the same set. One light deflector 3 is partially overlapped by one or two adjacent light deflectors 3 of the same set for preventing light from escaping. As a result, intensity and brightness of light received at the light guide is significantly intensified. Also, a gap exists between either two adjacent light deflectors 3 or one light deflector 3 and the edge of the reflector 2. The provision of gaps is to ensure adequate ventilation is provided and so overheating is prevented. Moreover, the light deflectors 3 of the same set are disposed slightly different to one another. Note that there is no restriction on the implementation of the light source 1. For example, the light source 1 can be implemented as either a CCFL (cold cathode fluorescent lamp) or LED (light emitting diode).

With reference to FIGS. 3 and 5, there is shown a reflecting apparatus for the backlight module of a plane display constructed in accordance with a second preferred embodiment of the invention. The second preferred embodiment substantially has the same structure as the first preferred embodiment. The difference between the first and the second preferred embodiments, i.e., the characteristic of the second preferred embodiment are detailed below. The remaining portion of light emitted from the light source 11 is substantially parallel directed to the distal light guide after it has been deflected by the light deflectors 31 and then reflected by the reflector 21.

Note that the section of the reflector 2 is a parabola. Also, the light deflector 3 can be implemented as either a concave lens of a cone or that of a cylinder (as shown in both embodiments).

With reference to FIG. 6, there is shown the whole backlight module in which light is substantially parallel directed to the light guide 4 after being reflected from the reflecting apparatus. Next, light is deflected to the plane display (not shown) as a backlight source of the plane display after passing the diffusers 51, 52.

Although the present invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US7578605 *Sep 6, 2006Aug 25, 2009Patrick Stuart MullinsLight shaping reflector system and method of manufacture and use
US7719021Aug 29, 2007May 18, 2010Lighting Science Group CorporationLight efficient LED assembly including a shaped reflective cavity and method for making same
US7898615 *Dec 29, 2007Mar 1, 2011Chimel Innolux CorporationBacklight module with light guide plate having partially overlapped reflective structures and liquid crystal display with same
US8079743Jun 23, 2006Dec 20, 2011Lighting Science Group CorporationDisplay backlight with improved light coupling and mixing
US8500308Oct 1, 2009Aug 6, 2013Opto Design, Inc.Light source device and illumination device using the same
US8721131 *Oct 2, 2008May 13, 2014Nichia CorporationLighting unit
US20100238660 *Oct 2, 2008Sep 23, 2010Nichia CorporationLighting unit
EP2333401A1 *Oct 1, 2009Jun 15, 2011Opto Design, Inc.Light source device and illumination device using the same
WO2008144650A1 *May 19, 2008Nov 27, 20083M Innovative Properties CoCollimating light injectors for edge-lit backlights
Classifications
U.S. Classification362/609, 362/297, 362/346
International ClassificationF21V7/00, F21V8/00, G02B6/00
Cooperative ClassificationF21Y2103/00, F21V7/005, F21V7/0025, G02B6/0051, F21V7/09, G02B6/0031
European ClassificationF21V7/00C, F21V7/09, G02B6/00L6I8R
Legal Events
DateCodeEventDescription
Jul 10, 2013ASAssignment
Effective date: 20130611
Owner name: CPT TECHNOLOGY (GROUP) CO., LTD., CHINA
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:CHUNGHWA PICTURE TUBES, LTD.;REEL/FRAME:030763/0316
Aug 20, 2010FPAYFee payment
Year of fee payment: 4
Jun 15, 2004ASAssignment
Owner name: CHUNGHWA PICTURE TUBES, LTD., TAIWAN
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:YU, HONG-TIEN;REEL/FRAME:015480/0942
Effective date: 20040604